photoshop_measure_points

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

With no annotations provided, the description carries the full burden. It usefully discloses the return values (pixel and normalized coordinates, vector distances, optional ratios) which substitutes for the missing output schema, but never states whether the tool mutates the document, nor mentions the fail-closed document_id behavior (that only lives in the schema).

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 filler. The core action is front-loaded, the outputs follow, and the scope caveat closes it out.

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?

Return values are described in prose, which compensates for the absent output schema, and the exclusion note prevents misuse. Still missing any statement about side effects or safety profile on the active document, which matters for a no-annotation 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?

Schema description coverage is 100%, so all four parameters are already documented in the schema, including the document_id fail-closed semantics and the maxItems limits. The description adds little beyond confirming that points are user-supplied and ratios are optional, 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 combination ('Measure user-supplied named points in the active Photoshop document') and enumerates the outputs, then explicitly delimits itself from adjacent landmark tools by saying it does not detect facial/anatomical landmarks automatically. An agent can distinguish this from photoshop_compare_landmarks and photoshop_transform_landmarks 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?

The phrase 'user-supplied named points' plus the explicit negative case ('does not detect ... landmarks automatically') tells the agent the precondition: coordinates must come from elsewhere. However, it never names the alternative tool to use when automatic detection is needed, so routing guidance is implied rather than stated.

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