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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is fully covered without the description. The description contributes useful domain context by naming the resource categories returned, but says nothing about behavior on a missing or malformed id, so the addition is modest.

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?

The core definition is a single front-loaded sentence that identifies the verb, scope and return types before anything else. The trailing attribution line is convention rather than content but costs little.

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 one-parameter read tool with full schema coverage and complete safety annotations, the description supplies everything an agent needs to call it correctly: what it returns and that it takes a single Datamart id. No output schema exists, but the description's naming of return categories partially compensates.

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% and the id property already documents its format with two concrete examples. The description adds one further example shape ("us.loc") but no syntax rules, validation constraints or id-namespace explanation beyond what the schema provides, so the baseline of 3 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?

States a specific verb and resource ("Get one Datamart resource by id") and enumerates the two record kinds it returns: a provider such as "us.loc" or a directory record like a library branch, school or college. An agent can distinguish this single-record fetch from the search-style siblings without opening the schema, though no sibling is named explicitly.

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?

Usage is implied rather than stated: fetch exactly one record when you already hold a Datamart id. There is no explicit routing to alternatives (e.g. profullstack_datamart_search) for the case where the id is unknown, and no statement about when not to call it.

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