get_collection_fields

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

Annotations already declare readOnlyHint=true, so the safe-read nature is covered. The description adds that the response includes allowed options, not just field names, which is useful. It says nothing about authentication, scoping by username, or caching/refresh behavior, so the added value beyond annotations is modest.

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?

Two short sentences with no filler; the resource definition is front-loaded ahead of the usage note. The parenthetical example list is efficient and grounds the abstract term "custom fields."

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 usefully states what comes back (fields plus allowed options), which is the most important unknown. However, the optional username parameter is undocumented everywhere, leaving a genuine gap for an agent deciding how to call it.

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 0%, so the description must carry the parameter burden, and it does not mention the username argument at all — an agent cannot tell whether omitting it yields defaults, the caller's own fields, or a global list. The only parameter-related content is the vague pointer to using returned ids with set_collection_field.

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 resource — custom collection fields and their allowed options — and gives concrete examples (Media Condition, Sleeve Condition, Notes). The retrieval verb is only implied by the noun phrase, but an agent can immediately tell this is the read-side counterpart to set_collection_field.

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?

"Use the ids with set_collection_field" establishes the workflow: fetch these field ids and feed them into the sibling mutation tool. It gives clear context for when the tool is needed, though it states no exclusions or prerequisites (e.g. whether the username argument is required for resolving user-specific fields).

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