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

Annotations already establish readOnly, idempotent, non-destructive, closed-world, so the burden is light; the description nonetheless adds operationally relevant context by disclosing 'Free, no authentication required' and 'Rate limited'. Its main gap is not describing the response shape, but that is covered by the output 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?

Three sentences, front-loaded with the computation itself, followed by scope exclusions and then practical notes. Every sentence adds information and none is filler.

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-only calculation with both annotations and an output schema present, this is complete: an agent knows the input meaning, the exact rates, the limits of applicability, and the auth/rate-limit situation. Nothing needed 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?

With 0% schema description coverage, the description must carry the parameter, and it does define the input as taxable income that is 'already-adjusted' and denominated in AED, which is meaningful disambiguation. It does not mention the 0 floor or the 1e12 ceiling present in the schema, so it stops short of fully compensating.

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?

Names a specific verb and resource ('Estimate standard UAE corporate tax') and pins the computation down with exact brackets (0% to 375,000, 9% above), so an agent knows precisely what is being calculated. It is clearly distinguishable from the VAT and real-estate VAT siblings even without opening their schemas.

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?

States the input condition explicitly ('on already-adjusted taxable income') and lists what the tool does not cover: deductions, free-zone rules, relief, and multinational minimum tax. That is strong when-not-to-use guidance, though no sibling alternative is named for those excluded cases.

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