mailkite_create_realtime_token

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

The annotations carry essentially no signal (all three hints are false), so the description carries the full burden — and it pays: it discloses five-minute expiry, single-use burn-on-first-use, scope inheritance from the calling credential, and the API-key requirement (mk_live_…). These are exactly the behavioral facts an agent needs and none are visible in the annotations or schema.

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?

Five sentences, each earning its place: core purpose, browser use case, expiry/burn/scope behavior, the stream-boundary clarification, and authentication requirement. Information is front-loaded with the primary verb and resource in the first sentence, with zero filler or repetition.

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 0-parameter tool with no output schema, the description covers purpose, context, behavior, lifecycle, and auth. The sole gap is that the return value (the token string) is only implied by 'this is what a page passes as ?token=' rather than stated explicitly; there is no output schema to compensate.

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?

The tool takes 0 parameters, so the schema description coverage is trivially complete and there is nothing for the description to annotate. With 0 params, the baseline is 4, and the description provides the relevant operational semantics (token lifetime, scope, auth) anyway.

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 first sentence gives a specific verb ('Mint') and a specific resource ('short-lived, single-use token for one Realtime API connection'). This clearly distinguishes the tool from all siblings, which handle webhooks, routes, templates, domains, sequences, and other mail/domain concerns. Even without the title, the purpose is unambiguous.

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 explains a concrete when-to-use: browsers where EventSource cannot set headers, where the token is passed as `?token=` instead of an API key in a URL. It also delineates the boundary of what the tool does not do ('the stream itself is GET /v1/realtime… contracted in sdks/spec/realtime.json rather than here'). It lacks an explicit mention of alternative tokens like scoped keys or app passwords, so it stops short of a 5.

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