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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is known. The description adds real value beyond them by disclosing the NOT_FOUND failure mode and the access-control nuance that a private Company the caller cannot see is indistinguishable from a missing one. It stops short of noting any pagination or field-truncation behavior, but for a single-record read that gap is minor.

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 tight sentences: the first front-loads what is returned, the second states the prerequisite. Every clause carries information and nothing is repeated from the schema beyond the necessary 'given its id' framing.

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 tool with no output schema, the description covers the three things an agent needs: what comes back (field list), how to get the required input (search/list_companies), and what failure looks like (NOT_FOUND). No material gap remains.

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 100% schema description coverage the parameter's meaning is already fully documented, and the schema itself says the id comes from search or list_companies. The description restates that provenance ('given its id') without adding format, length, or validation detail, so it neither helps nor hurts beyond the baseline.

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 and resource ('Read one Company in full, given its id') and immediately enumerates the fields returned, so the agent knows exactly what this retrieves. This clearly separates it from list_companies and search, which return collections rather than one full record.

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?

Explicitly tells the agent to call search or list_companies first to obtain the id, naming the sibling tools to use for discovery. The only preconditions the tool has are covered, leaving no ambiguity about how to obtain the required input.

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