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

No annotations are provided, so the description carries the burden. It discloses that the tool stops a recording and returns data, which is the core behavior. However, it does not disclose side effects such as whether stopping is idempotent, what happens if the sessionId is invalid, or whether resources are cleaned up. For a stop operation, this is a moderate gap but not misleading.

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?

One sentence, front-loaded with the action and resource, and it packs in the return-value summary without waste. Every word earns its place.

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 single-parameter stop tool with no output schema, the description is nearly complete. It explains what it stops, what it returns, and where the parameter comes from. The only missing piece is error/edge-case behavior, which is minor for this tool's simplicity.

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% and the single parameter sessionId is described as 'Session id from ios_performance_record_start'. The description reinforces this by referencing the start tool, giving the agent confidence about where the value comes from. This adds meaningful context beyond the schema's bare description.

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 states a specific verb ('stop'), a specific resource ('performance recording'), and explicitly ties it to its start counterpart (ios_performance_record_start). It also names the return payload (time-series + per-process summary), which distinguishes it from sibling tools like ios_performance_snapshot and android_performance_record_stop.

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?

The description clearly implies this tool is the stop counterpart to ios_performance_record_start, which is the primary usage context. It does not explicitly state when not to use it or name alternatives like ios_performance_snapshot, but the pairing with the start tool is strong enough guidance for an agent to select it correctly.

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