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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds value by disclosing the shape of the payload — computation semantics, models/options, and refusal behavior. It does not say how unknown or malformed tool names are handled, nor the response format.

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 tight sentences with no filler, and the core purpose is front-loaded. The trailing clause about the listing carrying only the opening is slightly awkward in phrasing but earns its place by justifying the tool's existence.

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 must convey return content, and it does so at a high level (computed behavior, models, options, refusals). It leaves open the response format, ordering relative to the input names, and error behavior for invalid names — gaps an agent would want closed for a lookup 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?

There is a single parameter with 100% schema description coverage ('tool names, as `tools/list` gives them'), so the schema carries the burden. The description's 'each named tool' only confirms that multiple names may be passed; it adds no format or constraint detail beyond the schema.

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 and resource ('the full description of each named tool') and enumerates the returned content (what it computes, models and options, refusals). It also implicitly separates itself from the catalog listing by noting that the listing only carries each description's opening. It does not name a sibling tool by name, but as a meta-tool it is unmistakable.

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?

It gives a clear selection condition: use this when the catalog listing's truncated opening is insufficient and you need the complete description. It stops short of explicit when-not guidance (e.g., how many names are reasonable per call, or that this should be used sparingly to save context).

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