Update a media item

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

Annotations already declare readOnlyHint=false (mutation) and idempotentHint=false (non-idempotent), so the behavioral baseline is known. The description adds the 'without re-uploading' nuance and lists fields, but does not disclose side effects such as whether unspecified fields are preserved or reset. This is adequate but not rich, given the annotation coverage.

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, clear sentence front-loaded with the action and resource, and it avoids repeating schema details. No wasted words; the key constraint (no re-upload) is included efficiently.

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 9-parameter mutation tool with full schema coverage and annotations covering the safety profile, the description covers the core purpose and a key constraint. However, the presence of edit_media introduces ambiguity about which tool to use, and the description does not resolve this, slightly reducing 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 100%, so every parameter is documented with a description. The tool description lists several fields (title, alt text, caption, description, attachment) but adds no new semantic meaning beyond the schema. Baseline 3 is appropriate when the schema carries the parameter documentation burden.

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 (update), resource (media item), and enumerates the fields (title, alt text, caption, description, attachment). It distinguishes from create by noting 'without re-uploading the file'. Although it doesn't address the edit_media sibling, the purpose is unambiguous and clear.

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 when updating existing media metadata without re-uploading, but it does not explicitly name alternatives or exclusion criteria. With an edit_media sibling present, there is no guidance on when to choose this tool over that one, leaving the agent to infer.

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