pi-delegate-mcp

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It discloses that partial output remains readable after abort, which is a useful behavioral detail beyond the simple action. It does not detail other side effects, but for a simple abort tool this is adequate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is one clear sentence with an additional clause. It is front-loaded with the main action and adds a relevant detail. No wasted words, though it could be slightly more structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the simplicity of the tool (one param, no output schema), the description covers the core action and a key consequence. However, it lacks details on error conditions, idempotency, or what 'running' means precisely. Acceptable but not comprehensive.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, and the description does not explain the sessionId parameter at all. The agent must infer that sessionId refers to the ID of the session to abort. With low coverage, the description should compensate, but it does not.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States the specific action 'Stop a running pi session' with a clear resource (pi session). It distinguishes from siblings like run, status, and spawn by focusing on termination. The verb 'abort' is reinforced by the description.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Implies when to use (to stop a running session) but does not explicitly contrast with alternatives. However, it does mention that 'Partial output stays readable via status', which hints at using status afterwards. No explicit when-not to use, but the mention of status provides some context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden, and it does disclose a critical behavioral trait: 'A delegate waiting on one is blocked until you answer it,' i.e. this call has a real unblocking side effect. It also explains the origin of requests (MCP adapter tool-approval and elicitation prompts), which helps an agent recognize legitimate questions. It omits permission/auth requirements for the caller and what a successful answer returns.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences, front-loaded with the core purpose and immediately followed by the operational detail (where to get requestId). No filler or restatement of the tool name. Slightly dense mid-sentence clause, but nothing wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 3-required-param, no-output-schema tool with no annotations, the description covers purpose, prerequisite lookup, source of requests, and the blocking consequence. The main remaining gap is that `sessionId` is never explained and there is no statement of what a valid answer looks like beyond the schema's `value` types.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 33% (only `value` is described), so the description must compensate. It does add genuine meaning for `requestId` by pointing to `status` as its source. However, `sessionId` is left entirely unexplained in both schema and description, so the compensation is partial.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb+resource ('Answer a question raised by a pi agent') that is clearly distinct from siblings like status, spawn, or steer. It scopes the tool to a narrow case (questions from pi extensions), so an agent can tell it apart from generic session tools. It stops just short of 5 because it never characterizes what an 'answer' does downstream beyond unblocking the caller.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a clear prerequisite chain: get `requestId` from `status`, and questions only exist for delegates spawned with `extensions: true`. That effectively tells the agent the condition under which this tool is callable. It doesn't state a when-not-to-use or name a fallback tool if no question is pending, so it falls short of explicit exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Given no annotations, the description carries the full burden. It discloses context preservation, immediate return (non-blocking), and the need to poll with `status`. It also states the pre‑condition (delegate finished). It doesn't cover error cases or side effects explicitly, but for this tool the key behaviors are well communicated.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences pack purpose, usage, alternatives, and behavior with zero filler. The primary instruction (use for finished delegates) is front-loaded, and each clause serves a purpose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple 2-parameter tool without an output schema, the description covers the essential workflow: when to use, what it does, and how to obtain results (poll via `status`). Minor gaps like error handling or repeated follow‑ups are not critical for an agent to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema documents the `prompt` parameter, but `sessionId` is left undocumented. The description does not add explicit meaning for `sessionId` beyond the name and context. With 50% schema coverage, this is borderline; the description could have compensated by explaining that `sessionId` identifies the finished delegate session.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clear action (send another prompt) targeted at a specific resource (a finished delegate) while preserving context. Explicitly distinguishes from spawn and steer, making the tool's purpose unambiguous even among many siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides direct guidance to use this instead of spawning a fresh delegate, and explicitly directs to `steer` for a working delegate. The when-to-use and when-not-to-use conditions are spelled out, leaving no ambiguity.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It clearly discloses the destructive effect ('Drop'), the target ('review history'), and the side effect ('freeing its id for reuse'). It does not mention irreversibility or error behavior, but the core behavior is transparent and specific.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single, front-loaded sentence with no filler. Every word contributes meaning, and the most important action ('Drop') comes first.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a one-parameter tool with no output schema, the description states the operation, the constraint (finished session), and the outcome (id reuse). It could have pointed to sessions for finding sessionId or to abort for running sessions, but nothing critical is missing for selecting and invoking the tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema gives no description for sessionId, so the description adds meaning by tying it to a finished session's id and explaining the reuse consequence. It does not explicitly name the parameter or explain where to find sessionId, but the parameter name plus the description make the intent clear.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Drop') and resource ('finished session from the review history'), and clarifies the consequence ('freeing its id for reuse'). It also distinguishes itself from abort by specifying the session must be finished.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies this is for finished sessions only, which separates it from running-session tools like abort. However, it never explicitly names an alternative or states when not to use this tool, leaving some routing inferred rather than stated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden, and it discloses the most important behavior: all other tools refuse until init runs. It also makes clear this is a reporting/discovery call, implying read-only use, though it does not explicitly address repeated-call safety or side effects.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences front-load the critical directive and include the refusal behavior without any filler. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a discovery tool with two optional parameters and no output schema, the description sufficiently lists what the agent will learn (reachable tools, default model, provider models, delegation recipes) and the prerequisite behavior, making it complete enough to call correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3. The description does not add meaning beyond the schema's existing explanations for cwd and models, though its mention of model listing aligns with the models parameter.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Reports') and names concrete resources: permitted tools, default model, provider models, and delegation recipes. It clearly positions init as the mandatory discovery/entry-point tool, distinguishing it from siblings like models, which only list models.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit ordering guidance: 'READ THIS FIRST' and 'Every other tool refuses until this has been called once.' This tells an agent exactly when to call init and that no sibling can substitute for it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It discloses the list scope (pi's scoped set plus custom providers) but does not mention side effects (none expected), output format, or ordering. For a read-only listing tool this is adequate but not rich; it does not contradict any structured data.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two succinct sentences. The main purpose and usage are front-loaded, with no filler or redundant wording. Every phrase earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple listing tool with two parameters and no output schema, this description covers the core purpose and usage. However, the `filter` parameter is left undocumented, and the description does not mention the return format or any caveats, leaving some operational details unspecified.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 50%: `cwd` has a description but `filter` does not. The tool description adds no meaning for `filter` or `cwd` beyond the schema, so the undocumented parameter remains unexplained. It fails to compensate for the schema gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'List models this delegate may use' with a specific verb and resource. It also specifies the scope ('pi's own scoped set plus any custom provider'), which distinguishes it from the sibling command-like tools (init, run, etc.) that perform actions rather than listings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says 'Use to pick a `model` value', giving clear context for when to invoke it. It does not mention when not to use it or name alternatives, but given the sibling set are mostly action-oriented commands, the guidance is sufficient for selecting it correctly.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden, and it discloses the most consequential trait: the call blocks until the delegate finishes, and it returns the final answer. It does not cover failure/timeout behavior, cost, or isolation of the delegate, which leaves some gaps for an unattended blocking call.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, zero waste, and the blocking constraint plus the routing guidance are front-loaded. Every sentence conveys a decision-relevant fact.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 7-parameter delegation tool with full schema coverage and no output schema, the description supplies the missing return semantics ('final answer') and the blocking contract, which the schema cannot express. Minor gap: no mention of what happens on delegate failure or timeout.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all seven parameters (including id, tools allowlist, extensions, model) are already documented in the schema. The description adds no syntax or format meaning beyond that, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Delegate a task to a pi agent') and clarifies the interaction model ('wait for the final answer'), then explicitly differentiates itself from the `spawn` sibling. An agent can distinguish this from spawn, spawn_batch, and follow_up without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Names the alternative (`spawn`) and the exact condition that selects it ('long work') versus the condition for this tool ('quick questions'). This is an explicit when/when-not/alternative statement, which is the top of the scale.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It does disclose that finished sessions remain readable until evicted and keeps the newest 50, which is useful behavioral context. However, it does not mention any authentication requirements, rate limits, or the exact return format (e.g., whether it returns summaries or raw session objects). For a non-destructive list operation, this is partial transparency but not exhaustive.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two tight sentences. The first states the core purpose, and the second adds a relevant retention policy. No fluff or redundancy; every word earns its place. It is front-loaded with the primary action and scope, making it easy for an agent to quickly grasp the tool's function.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the low complexity (2 optional params, no output schema, no annotations), the description covers the essential aspects: what it lists, the state scope, and retention behavior. It does not explicitly describe the output format, but for a list tool this is often inferable. The lack of an output schema is partially offset by the clear description of the tool's behavior, making it adequately complete for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, with both 'state' and 'verbose' already documented. The description adds no new parameter-specific detail beyond what the schema provides—it references 'running and finished' which maps to a subset of state values, but this is already inferred from the schema's enum-like description. Since the schema carries the parameter semantics, the description's contribution is minimal, aligning with the baseline of 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description begins with a specific verb and resource: 'List pi sessions held by this server, running and finished.' It clearly identifies the tool as a listing operation for sessions, and the mention of 'running and finished' distinguishes it from siblings like 'status' which likely targets a single session. The purpose is unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for listing sessions but does not explicitly contrast it with alternatives such as 'status' or 'forget'. No when-to-use/when-not-to-use guidance is provided, relying on the agent to infer when this tool is appropriate based on the action of listing. The retention note hints at review use cases, but no explicit routing to siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations present, the description carries the burden and delivers the single most important trait: it returns a sessionId immediately and nothing blocks, so the agent knows not to expect an inline result. It omits other behavioral context such as permissions, session lifetime/cleanup (handled by `forget`/`abort`), and failure behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with the core action and followed by the async contract and lifecycle routing. No filler; every sentence carries actionable information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 7-parameter, no-output-schema tool this covers what an agent most needs: the async contract and the follow-up tools for polling, steering and answering. Residual gaps are minor – return payload shape beyond sessionId and failure/timeout behavior are unstated.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already explains id, cwd, label, model, tools and extensions in detail. The description adds no parameter-level meaning beyond that (e.g. it never mentions the tools allowlist or model override), so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource: "Delegate a task to a pi agent running in the background," which is unambiguous. It implicitly separates itself from `run` via the timing heuristic ("more than a minute"), but never names `run` or `spawn_batch` explicitly, so sibling differentiation is inferred rather than stated.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives an explicit when-to-use rule ("anything that might take more than a minute") and then routes the agent through the full lifecycle: poll with `status`, redirect with `steer`, answer questions with `answer`. This is exactly the alternative-naming guidance an agent needs to pick and follow this tool correctly.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description fully covers behavioral traits: whole-batch validation before any start, failure semantics for bad model or duplicate id, and inheritance/override rules. It discloses key outcomes and edge-case behavior, though it does not mention async execution or session cleanup.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with no filler. The core purpose and key behavior are front-loaded; the polling guidance is a natural close. Every clause serves a purpose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given no output schema and no annotations, the description covers purpose, validation, inheritance, and polling—enough for correct invocation. Minor gaps like precise return format are covered by the `sessions` reference, so it is nearly complete for the complexity level.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with descriptions for all 6 parameters, so baseline is 3. The description adds meaningful semantics beyond the schema: it explains how batch-level defaults are overridden per task, clarifies the idPrefix format, and states the validation impact on parameters. This elevates it above the baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action: 'Fan out several delegates in one call.' It specifies the resource (delegates) and the batch nature, distinguishing it from the single-delegate spawn. The inheritance and validation details further clarify its exact role.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly advises polling with `sessions` instead of per-delegate `status`, giving concrete guidance on expected follow-up. It implies batch use case but does not explicitly contrast with `spawn` for single-delegate scenarios, leaving some room for inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It discloses the return contents (state, turn count, tools, latest text, pending questions) and explains the blocking semantics of the 'questions' array. It also notes that 'toolCalls' traces every tool run in order, adding behavioral depth beyond the tool name. It doesn't mention side effects, but 'check' implies read-only behavior, and the description sufficiently covers operational behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and well-structured: two sentences plus a note. It front-loads the purpose, then details the return fields and the blocking condition. Every sentence carries useful information with no fluff.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the absence of an output schema, the description adequately explains what the call returns and how to interpret the 'questions' array. It also clarifies the nature of 'toolCalls'. Minor omissions like error behavior for invalid sessions are not critical for a status-checking tool, so it feels complete enough for an agent to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 50%: only 'verbose' has a description; 'sessionId' is undocumented. The tool description does not mention either parameter, failing to compensate for the uncovered 'sessionId'. It doesn't explain what constitutes a valid sessionId or how 'verbose' changes the output beyond the schema's minimal hint. With low coverage and no description support, this is a significant gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a clear verb ('Check') and a specific resource ('background pi session'), and enumerates exactly what it returns (state, turn count, tools used, latest text, pending questions). This distinguishes it from siblings like 'sessions' (which likely lists sessions) and 'answer' (which handles questions). The purpose is unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives actionable guidance on how to interpret the result: a non-empty 'questions' array means the agent is blocked and must call 'answer'. However, it does not explicitly state when to use this tool versus alternatives (e.g., 'sessions' for listing all sessions, or 'steer' for modifying a session). The when-to-use context is implied but not contrasted with siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description bears the full burden of behavioral disclosure. It transparently explains the timing of when the message lands, which is a key behavioral trait. It does not mention error cases or lack of side effects, but for a simple steering action this is reasonably transparent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, concise, and front-loaded with the core action and timing. Every word adds value without unnecessary detail.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple tool with no annotations and no output schema, the description covers the primary use case and timing behavior. It lacks details on error handling or edge cases, but given the low complexity, it is fairly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% and the description does not explain the parameters at all. While 'sessionId' and 'message' are somewhat self-explanatory by name, the description fails to indicate which parameter identifies the agent or what the message content should be. The description should have compensated for the lack of schema documentation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('redirect') on a specific resource ('running pi agent') and adds timing context (after current tool call, before next model call). It explicitly contrasts with the sibling 'abort', making the purpose unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit guidance: use this instead of aborting when the agent is going the wrong way. This clearly tells the agent when to choose this tool over a direct alternative, leaving no ambiguity.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.