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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered; the description adds the one trait annotations can't express — the return format is Markdown. That is meaningful for an agent with no output schema, though it says nothing about error behavior for a missing slug.

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 sentences, front-loaded with what is returned and ending with the one input rule. The content enumeration is long but each listed field earns its place by signalling completeness of the record; minor trimming of 'and more' would tighten it.

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 tool with full annotation coverage and no output schema, the description supplies the two things structured fields cannot: the output medium (Markdown) and the breadth of returned fields. 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?

Schema coverage is 100%, so baseline is 3, but the description goes beyond the schema's terse 'Its slug, or its page address' by giving the concrete acceptable form 'around.iw.pe/b/…'. That clarifies the dual identifier formats rather than merely repeating them.

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 states a specific resource and scope: 'Everything ... about one business,' set against the sibling 'search_businesses,' so the one-vs-many distinction is unambiguous by name alone. It also enumerates the returned content domains (trade, town, address, phone, hours, services with prices), leaving no doubt what kind of record this fetches.

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 tells the agent what to pass and where that value comes from ('from search_businesses'), which establishes the intended search-then-fetch workflow. It stops short of an explicit when-not (e.g. don't use for lookups by name) or naming fallback behavior when the slug is unknown.

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