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

The annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, repeatable read operation. The description adds only the count (19) and the format (id + name) but doesn't disclose whether results are sorted, which is minor. It doesn't contradict annotations, and the added context is useful but minimal beyond what annotations provide.

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 a single compact sentence that front-loads the purpose and output format, and immediately connects to the sibling tool's usage. No wasted words; every clause 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?

Given the tool is parameterless and has an output schema, there is very little the description must cover. It fully explains the purpose, the data returned, and how the data is used in relation to a sibling. It could mention sorting or that it's a static list, but that is a minor gap; the description is complete for practical agent use.

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 tool has 0 parameters, so there is nothing to document. The description adds clarity about what the return data is (id and display name) even though no parameters exist. This gives the agent confidence about the output shape, which is valuable since the schema for parameters is empty.

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 ('Return'), a specific resource ('19 curatorial departments'), and the exact output ('numeric departmentId and display name'). It also distinguishes itself from siblings by noting these are the valid values for the met_search_collections departmentId filter, making it clear this is a reference/enumeration tool, not a search or retrieval tool.

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 explicitly says the output provides valid values for the met_search_collections departmentId filter, which tells the agent when to use this tool: when it needs to know allowed department IDs for filtering. It implies this is a preliminary lookup step before using search. It also indirectly contrasts with the siblings (get for single objects, search for queries).

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