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

Annotations already declare readOnlyHint=true and destructiveHint=false, so 'Read only' adds no new information. It does add one genuinely useful behavioral fact beyond the annotations: the need for a Cotlet API key with access to this app. That is the only extra context; no return format, pagination, or refresh semantics are described.

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?

The first two sentences are near-duplicates – 'Your Bayut Credits balance as Manage Listings shows it' and 'Returns the Bayut Credits balance shown in Manage Listings' convey the same fact twice. The auth and read-only notes are useful, but roughly a third of the text is redundant.

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 no-parameter, read-only balance lookup with no output schema, the description covers what is returned, that it is read-only, and the auth requirement. It is largely complete, though it could note whether the value refreshes live or is cached.

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 there is nothing for the description to disambiguate and the schema description coverage is 100%. Baseline 4 applies; no parameter text is needed or missing.

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+resource ('Returns the Bayut Credits balance') and names the app, which distinguishes it from the other balance/credits tools in the sibling list (e.g. property-finder_get_credits, bark_get_credit_balance). It never explicitly contrasts itself with those siblings, so it lands at 4 rather than 5.

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 says the balance matches what 'Manage Listings' shows, but gives no when-to-use guidance, no prerequisites beyond auth, and no alternatives or exclusions. An agent has no signal about when this is the right call versus other balance tools.

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