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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the description is free to add value elsewhere, and it does: it discloses the full set of returned fields, that a freshness date ('the date SafeResize checked it') is included, and a required user-facing disclaimer. It does not discuss rate limits or auth, but for a safe local read the added output context is meaningful.

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 dense sentence front-loads the resource ('Official photo rules for one document') and then enumerates the payload, followed by one actionable instruction. The enumerated list is long but each item carries information; there is no filler.

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?

With no output schema, the description correctly compensates by enumerating the returned fields, and it adds the confirm-on-official-source obligation. For a single-parameter read tool this is close to complete; only the upstream dependency on find_photo_requirements is left to the schema rather than stated in prose.

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% and the single document_id parameter is fully documented in the schema, including example values and its origin (find_photo_requirements). The description adds no parameter-level detail of its own, 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?

The description gives a clear verb+resource ('Official photo rules for one document') and enumerates exactly what comes back, so the agent knows precisely what this tool returns. It does not explicitly name the sibling it depends on (find_photo_requirements), though the input schema carries that routing, so it falls just short of full sibling differentiation.

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?

Usage is only implied: the agent can infer it should call this when it needs photo rules for a specific document ID. The only explicit guidance is a downstream instruction to tell the user to confirm on the official source. No when-not-to-use or alternative tools (find_photo_requirements, interpret_upload_rules) are named in the description itself.

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