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

Adds real context beyond the annotations: 'No sign-in' is an auth disclosure not captured by readOnlyHint/idempotentHint, and 'The move is not instant' warns about latency of the eventual action. It stops short of describing the return shape or any rate limiting.

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, front-loaded sentences with no filler. The core action (returns price) comes first, followed by the two key behavioral caveats.

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 should at least hint at what the price response contains (e.g., currency handling), and it leaves three of four parameters unexplained. Adequate for a read-only quote tool but with visible gaps.

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 description coverage is only 25% — currency is documented, but number, country, and number_type are bare in the schema and completely unmentioned in the description. With four parameters and three undocumented, the description fails to compensate.

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 rate-checker price to port an existing number to Widely. It clearly separates itself from siblings like get_port (status) and start_port (executing the move) by saying it 'does not start the move.'

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?

Implies the tool is a pre-move quote ('Does not start the move') but never names start_port or port_requirements as the alternatives to use next. The context is inferable rather than stated.

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