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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the mutation/risk profile is covered structurally. The description adds which actions mutate cohort membership versus cohort metadata, but says nothing about permissions, whether update is partial, or whether unlinking matches is reversible — real gaps for a destructive tool.

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 sentences, front-loaded with the verb/resource scope, then per-action requirements, then the sibling exclusion. No filler and nothing redundant with the schema.

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 7-parameter, 4-mode mutation tool with no output schema, the description covers action routing and required inputs well enough to call correctly. It is only slightly thin on what `update` can change and what a successful response looks like, though the absence of an output schema lowers the burden.

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?

With 0% schema description coverage the description must carry parameter meaning, and it does: it names the required parameters per action for 5 of the 7 parameters (name, startDate, endDate, cohortId, matchIds). It leaves `description` and the optionality/overlap of fields on the update path unstated, so it falls just short of full coverage.

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 specific verbs (create, edit, link/unlink) against a specific resource (cohorts and their cycle matches), and explicitly names the sibling it is not (delete_cohort). An agent can distinguish it from cohorts_query and delete_cohort without opening any 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?

Maps each `action` value to the parameter set it requires (create→name/startDate/endDate, update→cohortId, assign/remove→cohortId+matchIds), which tells the agent exactly which branch to invoke. It also explicitly routes deletion to delete_cohort, giving a clear when-not-to-use boundary.

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