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

Annotations already declare destructive=true and idempotent=true, yet the description adds what the agent actually needs: a missing variable is a not-found error and never falsely reported as deleted, the operation is audit-logged, and the org path needs an admin-scoped token. That is real behavioral context beyond the annotation set.

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?

Four short sentences, front-loaded with the action, then scope routing, then the error/idempotency guarantee, then the return shape. No filler.

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 supplies the return shape ({name, deleted: true}), the auth requirement, the scope-selection contract, and the not-found failure mode. Nothing material for correct invocation is missing.

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%, so baseline is 3, but the description adds the combination semantics the schema lacks: which parameters pair to select which variable scope, and that org needs elevated auth. It only omits the fact that `id` can be supplied instead of `name`, so the 'by name' phrasing under-describes the alternate key.

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 ('Delete an Actions variable by name') and immediately scopes it by the three variable tiers. The delete verb cleanly separates it from the get_variable/list_variables/set_variable siblings without needing to name them.

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 concrete when-to-use routing: owner+repo for repo variables, owner+repo+environment for environment variables, org for organisation variables, plus the admin-token prerequisite for the org case. It stops short of naming alternatives or stating when not to use it (e.g. use set_variable to update instead).

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