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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds value beyond that: default page size of 50, a hard cap of 100, a has-more flag, and the returned fields (id, name, creation time) — useful operational context an agent cannot get from the annotations.

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?

Three short sentences, trigger-first, with no filler. Every clause carries information: triggers, return shape, pagination policy, and the sibling exclusion.

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 single optional-parameter list tool with a full output schema and complete annotations, this description covers everything an agent needs: when to call it, what comes back, pagination ceiling, and what it is not for.

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 coverage is 100% and the limit parameter already documents its range and default ('1 to 100; defaults to 50'). The description's '50 by default and 100 at most' simply restates the schema, so 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?

States a specific verb+resource ('List your Croncool projects') and explicitly disambiguates from the sibling list_jobs with 'Not for listing jobs.' An agent can route between list_projects, list_jobs, and the other list_* siblings without opening a schema.

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?

Gives two concrete triggers ('when someone asks which Croncool projects they have' or 'a project's id is needed') plus an explicit exclusion ('Not for listing jobs'). This is when-to-use and when-not-to-use in a single breath.

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