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

Annotations already declare readOnlyHint=true, but the description adds valuable context: 'NO COST — pure discovery' clarifies it won't consume billing resources, and listing the enrichment fields (in_library, episode_id, transcription_status) sets expectations for what differs from the raw upstream data. No contradiction with 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?

Each sentence earns its place: purpose, cost/discovery, enrichment details, and actionable transition to next steps. It is front-loaded with the primary action and remains tightly structured despite covering multiple aspects.

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?

Given no output schema, the description appropriately mentions the key returned fields and even explains downstream ingestion paths. Combined with good annotations and schema, this gives an agent everything it needs to select and invoke the tool 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 75%, so the baseline is 3. The description does not add new meanings for max, since, before, or feed_id, but it implicitly references feed_id when suggesting transcribe_url. The schema already documents these parameters well enough; the description's main value lies in usage flow, not param semantics.

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?

The description opens with a specific verb+resource: 'Fetch the canonical episode list for a podcast directly from PodcastIndex'. It clearly distinguishes the tool from siblings like list_episodes (likely library-based) and browse_episodes by emphasizing upstream source and 'pure discovery'.

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?

Explicitly tells when to use the tool ('episodes you want to ingest') and provides concrete alternatives: call transcribe_url for new episodes or start_transcription for episodes already in_library. This is ideal usage guidance with named alternatives.

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