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

Adds substantial context beyond the annotations: exact price ($0.50 USDC on Solana), the x402 challenge-then-retry flow including the _meta["x402/payment"] key, the HTTP equivalent, settle-once replay protection, and that the returned watch id is the receipt. This is fully consistent with readOnlyHint=false, idempotentHint=false and destructiveHint=false, and it converts those hints into actionable behavior.

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 action, then economics, then the strongest warning (STATE-CHANGING / duplicate watch risk) in caps. Every sentence carries information an agent needs before paying; nothing is padding.

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?

Annotations and schema already cover the safety profile and both parameters, and no output schema means the id-as-receipt note suffices. The one gap is the lifecycle after registration — nothing says how or where to retrieve the daily results (trademarks_watch_changes) or what happens at day 30.

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 mark_text and the max-20 serial list are already documented in the schema. The description adds meaning about the watch's duration and cadence but says nothing further about parameter format or interaction (e.g., whether mark_text and serial_numbers can be combined). 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?

A specific verb+resource+cadence: "Register a 30-day trademark watch (daily checks)." An agent knows immediately what is created and how long it lasts. It does not explicitly name the sibling (trademarks_watch_changes) that reads results, so differentiation from siblings is implied rather than stated.

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?

Clear context for when to call: to start monitoring a mark or up to 20 serial numbers for new filings/status changes. It also gives operational guidance for the payment handshake and warns against blind retry after a timeout. What's missing is an explicit pointer to trademarks_watch_changes for polling results, which would complete the routing story.

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