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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds a genuinely useful behavioral fact beyond annotations: the call does not consume credits, which matters for a credit-metered service. It could go further on result limits or pagination, but the credit disclosure is real added value.

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 primary capability, then return fields, then chaining guidance, then the cost caveat. No filler and nothing out of order.

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 one-parameter search tool with an output schema already present, the description supplies everything else an agent needs: accepted input forms, key return fields for extraction, downstream tool chaining, and the credit cost. Nothing material 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% with a single documented 'query' parameter, so the schema already carries the load. The description echoes that dual free-text/URL intent and adds platform examples (Spotify, YouTube) slightly beyond the schema's example, but adds no format or parsing rules, so baseline 3 is right.

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 (search) and resource (published podcast episodes) plus the two accepted input modes (free-text query or pasted episode URL). Distinguishes itself from siblings like list_episodes and get_transcript by describing what it returns and how it differs from the back-catalog listing.

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 clear context for the two invocation modes and explicitly routes follow-up work to get_transcript (via id) and list_episodes (via podcast_id). No explicit 'do not use this when...' exclusion, so it stops short of the top score.

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