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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description goes well beyond that with refusal semantics, the de-duplication behavior ('joins an identical queued run instead of stacking another'), the required write access and 'repo' scope, and the exact return shape.

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 sentence is dense and front-loaded with the essential action, scope, and refusal rule before secondary details; parenthetical asides make it slightly cluttered but no sentence is wasted.

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 mutation tool with no output schema, the description supplies the auth requirements, refusal conditions, idempotency behavior, and the returned field names, leaving nothing an agent needs to invoke it correctly.

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 description coverage is 100%, so owner, repo, and run_id are already documented in the schema. The description adds no parameter-level format or constraint detail beyond what the schema provides, so the 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 and resource ('Re-run a failed or cancelled workflow run') and pins the scope ('at the SAME commit (same inputs, same PR merge preview)'), which separates it cleanly from siblings like gluecron_trigger_workflow, gluecron_cancel_workflow_run, and gluecron_get_workflow_run.

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-not conditions (a successful or still-running run is refused) and notes that per-job re-run does not exist yet, which tells the agent not to look for a granular variant. It stops short of naming sibling tools as explicit alternatives, so it is clear context rather than full when/when-not routing.

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