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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), yet the description adds genuinely new behavior: anonymous access is allowed, raw audio/manuscript access is excluded, and empty matches return empty rather than synthesized results (an anti-hallucination guarantee an agent needs).

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?

Front-loaded with the core action, then progressively adds filtering rules, return fields, and boundaries. Every sentence carries information, though the return-field sentence partially overlaps what an output consumer would infer and could be tightened.

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?

Even without an output schema, the description enumerates the returned artifacts (source IDs, content hash, language/section/stanza info, listening links), states the access model, and defines the empty-result behavior, leaving nothing essential for correct invocation unstated.

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 the schema already documents all three parameters including exact semantics and the note that receipt_id/idempotency_key are unread. The description restates the query behavior but adds no syntax or format detail beyond what the schema provides, so 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 (search and retrieve) and a precise resource (author-verified public Cassie Hour lyrics), with the scope narrowed by 'author-verified public' so it is distinguishable from siblings like search_cassie_hour_fragments and get_public_story_record.

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 explains the two operating modes (omit/empty query returns the full record; nonempty query filters by substring) and states boundaries (no raw audio, no manuscript access). It stops short of naming an alternative sibling tool for overlapping needs, 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.