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

Annotations already declare read-only, idempotent, non-destructive, open-world behavior. The description adds value beyond that by disclosing the auth requirement ('Requires a CanonCannon API key via _apiKey') and what the call returns (episode count and metadata), which the annotations do not cover.

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 tight sentences that front-load the resource description, then the slug source, then the auth requirement, capped with a concrete call example. No filler, and the example earns its place by showing exact argument shape.

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 simple two-parameter read tool with no output schema, the description covers the resource, the slug origin, the auth requirement, and the return shape (episode count + metadata). It is nearly complete, with only the absence of any mention of error or not-found behavior as a minor gap.

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 both parameters are documented in the schema, so the baseline is 3. The description reinforces the slug's origin ('from canon_podcast_list') and provides a worked example, but adds no syntax or format detail beyond what the schema already supplies.

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 resource ('One tracked show from CanonCannon') with clear scope ('with its episode count and metadata'), so the agent knows it fetches a single show. It references canon_podcast_list but only as the source of the slug, not as a contrastive alternative, so sibling differentiation is implied rather than explicit.

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 concrete prerequisite ('Get the slug from canon_podcast_list') and the auth requirement, which strongly implies the intended workflow. However, it never states when to prefer this over alternatives like canon_episode_get or canon_podcast_list, so usage is only implied.

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