Verify MoMo credentials

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered; the description still adds real context by naming the three credentials consumed and disclosing that it performs a live token-mint call (i.e., it hits the network and will fail on bad credentials). 'Moves no money' is a useful explicit reassurance beyond the annotations, though failure behaviour and whether a token is returned are left unstated.

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?

Two short sentences with no filler; the operational claim comes first and the safety caveat second. Every clause carries information the agent needs.

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 zero-param, no-output-schema tool the description covers what is checked and the network/money-safety profile, which is nearly everything. It stops short of saying what a success or failure looks like (token returned vs. thrown error), which would fully close the loop given there is no output schema.

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 zero parameters, so per the baseline there is nothing for the description to disambiguate and a 4 is appropriate. The description does usefully explain that the credentials are implicit (environment-configured) rather than arguments.

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?

Specific verb ('Check') and resource (the subscription key / API user / API key trio minting an access token), which clearly separates it from money-moving siblings like momo_request_to_pay and from momo_check_account_active (account status, not credential validity). It never names a sibling explicitly, so the differentiation is inferential 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?

There is no explicit when-to-use or when-not-to-use statement and no alternative tool is named. The phrase 'Moves no money' implicitly signals a safe pre-flight/sanity check, which an agent can reasonably read as 'call this before live payment calls', but that is inference rather than guidance.

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