twitter_customer_session_status

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

Annotations already mark it read-only/non-destructive, and the description goes well beyond that: it enumerates the returned fields, discloses the security posture (never returns auth_token, ct0, or proxy URLs), states cost ('Free'), and explains scoping by construction ('takes no account identifier of any kind, so it cannot read another key's session'). This is exactly the extra behavioral context annotations cannot carry.

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 core action, then return fields, then use cases; every clause carries information. It is dense and delivered as one long run-on paragraph rather than being broken into scannable chunks, which slightly hurts structure but not substance.

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?

There is no output schema, so the description carries the full burden of describing the response — and it does, enumerating every field, the enum-ish values for status and egress.source, and what is deliberately withheld. Nothing an agent needs to call 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?

Zero parameters, so the baseline is 4. The description earns that by explaining the absence functionally — no account identifier of any kind, scoped to the caller's own API key — which tells the agent the empty schema is intentional rather than an omission.

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 and resource ('Read back the X account session you registered with') and immediately demarcates it from the sibling twitter_customer_session ('without changing it'). An agent can tell this apart from twitter_customer_session, twitter_customer_session_delete, and twitter_account_me without opening any 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?

Gives concrete use cases ('am I posting as the account I think I am', 'has my session expired', 'is the proxy I supplied actually being used') and contrasts with the registration sibling, so context is clear. It stops short of an explicit when-not-to-use statement (e.g. use twitter_customer_session to register, this to inspect), leaving that routing to inference.

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