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

Annotations already cover the safety profile (readOnly, non-destructive, not open-world), so the bar is lower. The description adds genuine context beyond them: the tool is state-dependent on previously retrieved results, performs no search, and is intended for a separate rendering step in a client pipeline. It says nothing about what the rendering produces, but the output schema exists to carry that.

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 short sentences, front-loaded with the purpose, then inputs, then the routing constraint. The sentence restating the accepted inputs is low-value since the schema carries it, but nothing else 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?

Purpose, usage and the no-search constraint are well covered, and return values are handled by the output schema. The gap is the fully undescribed nested schema: for a rendering tool whose inputs are file paths and platform ID maps, the agent gets no guidance on what those fields should contain.

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 0% and the nested track objects use opaque fields (map_path, audio_path, artist_path, platform_ids) that are never explained. The description does name the three parameters and marks hashtags optional, which partially compensates, but it adds no meaning about required nested fields or path 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?

States a specific verb and resource: displays previously retrieved similar-track results in an interactive audio player. It explicitly distinguishes itself from find_similar_tracks by declaring it does not perform a new search, so an agent can pick between them without opening either schema.

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 an explicit when-not ('Does not perform a new search') plus the condition that selects this tool ('clients that use a separate rendering step') and names the alternative sibling ('find_similar_tracks also supports direct rendering'). This is a complete routing rule.

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