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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds a genuinely useful behavioral fact: 'No authentication required,' which an agent cannot infer from the schema. It does not say whether the check is idempotent, pollable, or what happens for an expired/unknown session.

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?

Three short sentences with zero filler: purpose first, then how to obtain the parameter, then the auth fact. Each sentence carries distinct information.

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 read with no output schema, the description never indicates what a status response looks like (e.g. pending vs paid vs failed) or whether it should be polled. The input side is fully covered, but the return side is left entirely to inference.

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 the baseline would be 3, but the description adds provenance beyond the schema by naming the specific tools that produce the session_id. That is the key piece of semantic context an agent needs to supply a valid value.

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: 'Check the payment status of a job posting.' This is clearly distinguishable from siblings like create_company_job, update_company_job, and purchase_job_extras, which are the mutation steps of the same flow.

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 places the tool in the purchase lifecycle by naming the three sibling tools whose returned session_id feeds it, which tells an agent when this tool applies. It stops short of explicit when-not conditions or stating that it should not be used with arbitrary Stripe session IDs from elsewhere.

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