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

Annotations already declare read-only, non-destructive, and closed-world, so the bar is lower, yet the description still adds real boundaries: facts are sourced from Portaur's own site and it never returns prices, client names, or private data. That negative scoping is valuable behavioral context beyond the annotations. It stops short of describing response format, though no output schema exists to cover that gap.

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?

Front-loads the identity and payload in the first sentence, then adds provenance and exclusions in short, non-overlapping clauses. No filler and nothing that could be cut without losing routing information.

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?

With zero parameters and no output schema, the description carries the burden of telling the agent what comes back, and it does so by enumerating the fact categories plus an explicit exclusion list. Nothing an agent needs to call this zero-argument tool 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?

The tool takes no parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies. The description correctly does not waste space restating an empty schema.

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 plus resource ('Returns facts about Portaur LLC') and enumerates the content the caller can expect: identity, mission, founder, contact, and public page links. This clearly differentiates it from siblings like list_services or contact_options, which cover narrower slices of company information.

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 implies usage by scoping the tool to published company facts and stating 'Read only', but it never says when to pick this over ask_portaur (a free-form question tool) or contact_options. The agent must infer the boundary from the returned-content list alone.

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