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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by clarifying that the time is the server's machine clock in UTC (not the caller's local time) and that a caller-supplied timezone only adds a local rendering – a meaningful, non-obvious semantic.

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?

Purpose is front-loaded in one sentence, followed by usage rationale, then args and returns in compact list form. The Returns block is largely redundant with the existing output schema, which costs a little length, but the overall structure is clean and skimmable.

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 zero-required-parameter, read-only utility with an output schema present, the description covers purpose, usage motivation, and parameter intent. An agent has everything needed to call it correctly; the duplicated return block is harmless redundancy rather than a gap.

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 both parameters are already documented with constraints and defaults. The description restates them (IANA zone example, default 'markdown') without adding syntax, fallback behavior for invalid zones, or offset semantics, so it sits at 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 first sentence names a specific verb and resource ('Return the current time of the machine running this server') and scopes it precisely to UTC plus an optional IANA time zone. No sibling tool (identification, history, summarize, risk score, webhook verification) overlaps with this, so differentiation is implicit and 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 concrete when-to-use scenarios tied to sibling concepts: judging whether an identification's observed_at is older than a 5-minute window, or how long ago an account was last seen. It lacks any when-not-to-use or named alternative, but no plausible alternative exists among the siblings, so the guidance is nearly complete.

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?

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=true. The description adds genuinely useful behavior beyond that: the ~10 s wait for a new identification, possible truncation via truncated/truncation_message, and the caveat that catalog typical weights can drift and out-of-catalog signal names are possible.

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?

Well front-loaded with the purpose first, then Args and Returns. However, the large Returns block restates the full response shape even though an output schema already exists, so a meaningful portion of the text duplicates structured data rather than earning 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?

Output schema exists, so return values need no further explanation, and all three parameters are documented. The description still covers the pieces an agent needs: latency, truncation, the 999 rate-limit marker, band ranges, catalog drift caveats, and a pointer to the shieldlabs://reference/risk-signals resource.

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 baseline is 3. The description goes beyond the schema by adding the mutual-exclusion constraint ('exactly one of request_id and identification') and the validity rule that a pasted risk_score must be an integer 0-100 or the 999 marker with integer weights — constraints not encoded in the schema.

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 ('Explain why an identification got its Risk Score') and enumerates exactly what is explained: band, weighted signals, detection flags, connection type, caveats. The purpose is unmistakable and functionally distinct from shieldlabs_get_identification, but no sibling is named in the description itself, so the differentiation is only implicit.

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 a concrete operating rule — 'Give exactly one of request_id and identification' — and explains the two modes: reading from the History API versus explaining a pasted identification. It does not state when to prefer this tool over shieldlabs_get_identification or shieldlabs_search_history, so exclusions are absent.

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?

Beyond the readOnly/idempotent annotations, it discloses non-obvious asynchronous behavior: the row appears 1-3 s after the browser call, can be refined for ~10 s, and the tool returns the first version found, with the rule to re-read once observed_at is ~10 s old. It also documents polling semantics and that 429/5xx/network errors do not terminate the wait while a bad key does, plus that a missing identification must be treated as unverified, never clean.

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 purpose and the async-timing caveats are front-loaded and each earns its place, but the verbatim Args and Returns blocks duplicate the input schema and the existing output schema, adding bulk without new 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 read tool with annotations covering safety, a 100%-covered schema, and an output schema, the description covers the remaining gaps: async timing, polling and error semantics, and the correct interpretation of a missing verdict. Nothing an agent needs to call it correctly is missing.

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 request_id, wait and response_format are already fully documented in the schema, including the UUID pattern and defaults. The description's Args block largely restates that, though it does add the operational hint that wait=false suffices to re-read a refined verdict.

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 first sentence names a specific verb (Read) and resource (the verdict of one identification by request ID) and enumerates the concrete payload fields returned. It is clearly distinguishable from siblings like shieldlabs_search_history or shieldlabs_summarize_entity, which operate on entities rather than a single request ID.

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 states exactly when to use it ('when you have the request ID of a protected action ... and need its verdict') and adds the key situational fact that the browser only sees the request ID while the verdict must be read server-side. It also names alternatives in Next steps (shieldlabs_explain_risk_score, shieldlabs_summarize_entity) and gives the re-read condition.

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?

Annotations already declare readOnly/idempotent/openWorld/destructive=false, and the description goes well beyond them: pre-request validation refusal, IPv6 not searchable, User HIDs containing '/' unsearchable, 401 = wrong key, and a concrete 429 rate limit (~15 req/s per domain). It also flags that results contain untrusted data via untrusted_data_note and possible truncation.

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?

Front-loaded with the purpose and the routing decision, then organized into Args/Returns/Examples/Errors sections that are each useful. It is on the long side and the Args block overlaps the schema, but no section is padding.

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?

Despite an output schema existing, the description adds the paging contract (next_offset, has_more) and error semantics an agent needs to drive the loop correctly. For a 5-parameter, enum-heavy search tool, nothing material is missing.

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's Args block largely restates the schema but does reinforce value formats and adds concrete examples (type="user_hid", type="device_id", reusing offset=next_offset), which clarifies how the parameters combine in practice.

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 opening sentence states a specific verb (list), resource (identifications for one identifier from the History API), ordering (newest first), and paging behavior. It explicitly distinguishes itself from the sibling shieldlabs_summarize_entity, so an agent can route between the two without opening a 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?

It names exactly when to use this tool (individual identifications of an account, device, visitor, cookie, visit or IP) and when to prefer the alternative (counts and aggregates over many identifications -> shieldlabs_summarize_entity). Worked examples cover the three main call patterns, including how to page.

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?

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), but the description goes well beyond them: it discloses that results are server-computed from the returned window rather than a ShieldLabs verdict, documents which values are excluded from counts (null, 'anonymous', 'fail', '-1', 'unknown', all-zero device ID, 999 rate-limit marker), and warns about the shared ~15 req/s History API limit.

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?

Front-loaded with purpose, then use cases, then args, then behavior; each section is dense and earns its place. The verbose Returns dump is largely redundant with the existing output schema, which is the only real conciseness cost.

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 4-parameter aggregation tool with an output schema and full annotations, the description covers identification of scope, counting semantics, edge cases, rate limits and output format. An agent has everything needed to call it correctly and interpret the result.

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 baseline is 3, but the description adds real meaning beyond the schema: value formats (UUID for ID types, dotted IPv4 for ip, exact User HID), the 'anonymous' special case, the '/' restriction, and the cost model for max_items (each 100 identifications = one History API request from a shared limit).

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 (Aggregate) and resource (recent History API identifications) and enumerates the five entity types it operates over. It explicitly distinguishes itself from the sibling tool by directing the agent to shieldlabs_search_history for individual identifications.

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 concrete when-to-use questions ('how many accounts used this device', 'whether an IP sent automated traffic') and names the alternative (shieldlabs_search_history) with the condition that selects it. It also advises starting with the default max_items and raising it only when the window is incomplete.

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?

Beyond the read-only/idempotent/non-destructive annotations, the description discloses a security guarantee ('never returns a secret or an expected signature'), the 64 KB size boundary and the fallback diagnostic of testing common body mutations when a signature mismatches. It also surfaces the deployment-specific fact that SHIELDLABS_WEBHOOK_SECRET is unset on this server, forcing the caller to pass secret.

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?

Purpose and scoping come first, then the signature/rotation semantics, then args and return shape — well front-loaded and dense. It is on the long side and the Args/Returns blocks partly restate the schema and output schema, which is mild redundancy but also serves as a quick reference.

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 five-parameter verification tool with an output schema present, the description covers the environment prerequisite, signing algorithm, rotation handling, mismatch diagnostics, and privacy guarantees. Nothing an agent needs in order to call it correctly is missing.

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, but the description adds real semantic content: the signature format is 'sha256=' plus lowercase hex HMAC-SHA256 keyed with the full secret including the whsec_ prefix, and multiple secrets are comma-separated with matched_secret reporting which one hit. These are interaction details the per-parameter schema text does not fully convey.

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 and resource — check whether a received ShieldLabs webhook delivery's X-Shield-Signature header matches the raw body for the endpoint's signing secret. No sibling tool (identification, search history, summarize entity, explain risk score, current time) overlaps with signature verification, so no sibling disambiguation is required.

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 states the context explicitly — 'For debugging a webhook endpoint' — and then covers the rotation scenario where multiple comma-separated secrets should be supplied. There is no explicit when-not guidance, but the tool's scope is narrow enough that no plausible alternative exists among the siblings.

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