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

With no annotations, the description carries the full burden. It discloses that the result is an exhaustive catalogue ('Every provider') and that each entry includes a signup_url, which is useful. However, it does not mention potential response size, ordering, pagination, authentication, or rate limits. This is adequate for a simple read-only list but not richly transparent.

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 concise sentences with no filler. The core behavior is stated first, and the usage guidance follows immediately. Every sentence earns its place.

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-parameter, no-output-schema list tool, the description covers the return contents and when to use it. It lacks details like whether provider IDs are included or whether pagination exists, but those are minor omissions given the tool's simplicity.

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 input schema is empty and schema description coverage is 100%. With zero parameters, there is nothing for the description to explain; the baseline of 4 applies.

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?

The description uses a specific verb ('list') with a clear object ('every provider in the catalogue') and adds the returned field 'signup_url'. It also distinguishes itself from plan-focused tools by stating this is for brand-level questions 'rather than a specific plan.'

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?

It explicitly states when to use the tool: 'Use this when the question is about a brand rather than a specific plan.' This provides clear context and an exclusion, though it does not directly name the sibling tools as alternatives in the description.

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