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

With no annotations, the description carries the behavioral burden. It usefully discloses that the artifact is 'held, not rendered', returns an artifactId, and is part of a 2-step lifecycle. It does not mention persistence, ordering constraints, or permission requirements, but the core observable behavior is clearly 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?

The description is focused and each sentence earns its place, including the return value and the concrete example. It is slightly dense with the phrase 'Instanced Manifestation' and the parenthetical lifecycle note, but remains efficient and readable.

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, the description is largely complete: it covers the resource, the behavior, the intended use case, and the return value. It leaves minor questions about sourceUri applicability and any side effects, but does enough for an agent to select and 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 100% for the two parameters, so the schema already explains sourceUri and description. The description adds value by showing the intended content of the description parameter: 'this is what I want the presence to look like'. It does not add anything specific about sourceUri.

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 precise action: 'Adds a Gaussian splat artifact (or other content asset) to the substrate as reference material'. It also distinguishes this tool from siblings by explaining the artifact is 'held, not rendered', and positions it as step 1 in an add/retire lifecycle.

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 guidance: 'Use this to give spawnPresence something concrete to build from' and contrasts with 'describing appearance in prose'. The add/retire pairing also implicitly names retireArtifact as the opposite operation.

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 burden. It states it 'feeds new content' and is 'step 2 of 3', which implies mutation but not the clarity of whether it modifies state irreversibly. It doesn't omit major behavioral aspects, but lacks details like whether it is asynchronous, or if it returns a confirmation. This is a neutral, not very rich disclosure.

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 sentence, front-loaded with the purpose and step. It gives a concrete example of input ('words to say') without verbosity. Every word earns its place, and it is appropriately targeted for the agent.

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 2-parameter schema and a clear lifecycle context, the description is fairly complete. It doesn't have an output schema, but for a feeding operation, an agent can infer it returns nothing. It lacks details on return value or behaviour on non-existent presenceId, but this is minor given the overall simplicity.

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 50%: parameter 'text' has a description, but 'presenceId' does not. The description adds meaning by relating 'text' to 'words to say', which partly compensates for the schema gap; however, 'presenceId' remains semantically weak. Baseline is 3 since coverage is moderate.

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 verb 'feeds' and the resource 'presence', and it identifies its place in a 3-step process. It differentiates from siblings by mentioning 'spawnPresence' and 'retirePresence', though it doesn't explicitly contrast with them. The title 'Drive an existing presence' also reinforces the action.

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 implies usage as step 2 of 3, after spawnPresence Illustrates when to use, but it doesn't provide explicit when-not-to-use or alternatives. The context is clear enough to understand the lifecycle, but there is no mention of conditions to avoid using or of the sibling 'manifestHighlight'.

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 must carry the behavioral burden. It discloses 'ephemeral' and 'temporary' to indicate the non-persistent nature of the highlight, but it does not explicitly state that the tool modifies no underlying state or that the highlight fades without side effects. This leaves some room for agent interpretation.

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 consists of two concise sentences. The first imparts the core action and scope, and the second offers a practical usage tip. There is no fluff, and the information is front-loaded, making it easy for an agent to scan and apply.

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 drawing tool with no output schema, the description covers the core behavior and usage preference. It could mention the optional duration parameter or its bounds explicitly, but those are already in the input schema. The tool's behavior is sufficiently explained, though there is no clarification about its relationship to sibling manifestation tools, which slightly detracts from completeness.

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 50%; the description parameter is already well documented (with an example), and the tool description aligns with it ('described on-screen content'). However, the description says nothing specific about durationSeconds beyond the schema's default/range, so it does not add meaningful semantic value to that parameter. Since the coverage is exactly at the threshold, the description provides only marginal added insight.

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 it 'Draws a bounded, temporary highlight over the described on-screen content', identifying the specific action and target. However, it does not directly differentiate from sibling tools such as spawnPresence, so it falls short of full 5 for sibling awareness.

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 sentence 'Prefer this over describing a location in text when the user can see their screen' gives a clear context for when to use this tool. It does not mention alternatives like sibling manifestation tools, but the guidance is explicit about a common alternative.

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 burden of disclosing behavior. It clearly indicates a destructive operation ('Removes') and the slot-freeing effect, but it does not mention irreversibility, idempotency, error behavior, or any side effects beyond the slot release.

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 very concise and front-loaded with the key action. The phrase 'Instanced Manifestation, step 2 of 2' adds workflow context, though it is slightly cryptic. Overall, every word 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 one-parameter operation, the description is adequate but has clear gaps: it does not describe what happens if the artifact is not held, whether the retire is reversible, what response to expect, or how this step connects to the full manifestation workflow.

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 contains only artifactId with no documentation, so the description partially compensates by clarifying that the removed entity is a 'held artifact.' This makes the artifactId's role inferable, but the description does not explicitly state that artifactId is the identifier of the artifact to retire or explain any format expectations.

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 ('Removes a held artifact') and the resource ('artifact'), with an additional consequence 'frees its slot.' The phrase 'step 2 of 2' provides context but does not clearly differentiate this tool from sibling tools like retirePresence.

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 within a two-step workflow ('step 2 of 2'), suggesting it should follow a prior manifestation step. However, it does not explicitly state when to use this tool versus alternatives such as addArtifact or retirePresence, leaving the choice to 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, the description carries the full burden. It discloses that the operation is 'clean' and frees a slot, implying it's not destructive in a harmful way but is a cleanup action. It does not mention any side effects like throwaway resources, idempotency, or failure behavior, so it's adequate but not rich.

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 with no filler. The first sentence is front-loaded with the verb and purpose, and the second provides the usage guidance. Every word 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 one-parameter cleanup tool, the description is complete enough. It explains the lifecycle context (step 3 of 3), the benefit (frees slot), and the necessity (concurrency cap). It does not detail the output or error states, but given no output schema and the clear action, this is sufficient.

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?

There is only one parameter, presenceId, with 0% schema description coverage, but the description implies it identifies the presence to retire by referencing 'a presence created by spawnPresence.' It doesn't state that presenceId must be a valid ID from a previous spawn, but the context is reasonable. The description adds minimal extra meaning beyond the schema's property name.

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 tool's action ('Cleanly ends a presence'), the resource it applies to ('created by spawnPresence'), and its role in a sequence ('step 3 of 3'). It does not explicitly distinguish from siblings like retireArtifact, but the context of presence is specific enough to avoid confusion.

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 provides an explicit 'when to use' directive: 'Always call this when the presence is no longer needed.' It also explains the rationale — 'concurrent live presences are capped' — signaling that cleanup is important. However, it does not describe when NOT to use it (e.g., if the presence is already ended) or alternatives.

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 behavioral burden. It does disclose that the presence is persistent, that generative work happens 'inside this contract,' and that 'the contract itself never changes,' plus the return of a presenceId. However, it omits side-effect details such as whether an artifact is consumed, whether spawning twice overwrites, or permission requirements, and the final sentence is somewhat cryptic.

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 compact and front-loaded with lifecycle context before diving into parameters and return values. The final sentence about 'generative work' is somewhat vague and may not earn its place as clearly as the rest, but overall the structure is efficient.

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 tool with 3 parameters, no annotations, and no output schema, the description covers the essential context: what it creates, how it relates to addArtifact, what it returns, and what to do with that return value. It is reasonably complete, though a note about error conditions or idempotency would make it fully self-sufficient.

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 already covers 100% of parameters, and the description adds meaning beyond it: it gives a concrete example for sourceContext, explains that artifactId is an alternative to fresh derivation, and clarifies that styleHint is optional. This enriches the bare schema descriptions without redundancy.

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 names a specific verb and resource: 'Creates a persistent presence derived from the given context.' It also positions the tool as 'step 1 of 3 (spawn / animate / retire)' and references animatePresence and retirePresence by name, making it easy to distinguish from the siblings and from addArtifact.

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 lifecycle is explicit: this is step 1, the returned presenceId feeds animatePresence and retirePresence, and the tool can be used either from fresh context or from a held artifact via addArtifact. It does not explicitly state when not to use it (e.g., versus manifestHighlight), so the guidance is clear but not exhaustive.

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