Document Player

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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=false) by disclosing the focus-mode/live-speech rendering, that it returns a private reader link, that it will not open a browser or confirm playback, and that new passages appear in an already-open reader. These are exactly the side-effect expectations an agent needs for a non-idempotent send operation.

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, front-loaded with the primary action and followed by the delivery constraints. No filler or restatement of the title.

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?

With no output schema, the description compensates by explaining what is returned (a private reader link) and, critically, what is NOT returned (no playback confirmation, no browser opening). Nothing needed to invoke it correctly 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 description coverage is 100%, including the non-obvious request_id retry semantics ('Reuse this unique ID when retrying the same passage'), so the schema carries the parameter burden. The description adds no parameter-level detail beyond that, which is the correct baseline when the schema is complete.

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 (send) and resource (text to the user's Doc Player browser reader), then immediately clarifies the mode (focus mode, live speech). An agent knows exactly what the tool does without opening the 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?

Usage is implied by the description of the effect rather than stated as when-to-use guidance, and there are no siblings to differentiate from. The note that it 'does not open a browser or confirm playback' helps set expectations but is framed as behavior, not selection guidance.

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