watchlist_create

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

With annotations only declaring readOnlyHint=false, openWorldHint=true and destructiveHint=false, the description carries real weight: it discloses the HMAC signing scheme and header format, that the secret is shown exactly once, the per-event billing model, that charging occurs only on a 2xx webhook response, and the 20-active limit. This is behavior an agent cannot infer from the structured fields.

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?

Roughly five short sentences, each carrying distinct information (resource definition, delivery/signing, billing, secret visibility, quota), with the core purpose front-loaded. No filler or repetition 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?

For a mutating tool with no output schema, it covers delivery mechanism, signing, cost, secret handling and quotas, and it describes the returned secret that the schema cannot convey. What it omits is marginal—authentication expectations and any note on how filters interact with existing alerts—so it is nearly complete but not exhaustive.

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%, so name, filters and webhook_url are already documented, including the constraint that at least one funding_search filter is required. The description restates the filters-plus-webhook composition but adds no per-parameter syntax or format guidance beyond the schema, so the 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?

The description gives a specific verb and resource ('Save a funding-signal alert') and immediately defines the resource composition: funding_search filters plus an https webhook. It names the related sibling funding_search, so an agent can distinguish this from watchlist_list/watchlist_get without opening schemas.

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?

It supplies operating context (free to create, $0.02 per delivered event, 20-active cap) but never states when to pick this over siblings such as watchlist_test or how to validate a webhook before creating. Usage is implied by the resource definition rather than explicitly directed.

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