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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety and idempotency profile is fully covered without the description's help; nothing here contradicts them. The description adds no behavioral context of its own, such as what happens when the id does not exist or whether the read is tenant/workspace scoped.

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?

A single short sentence with zero filler, and the identifying detail ('by id') is not buried. It is perhaps too terse rather than bloated, so it loses a point for under-specification rather than verbosity.

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 simple one-parameter read with rich annotations and full schema coverage, the essentials are present. With no output schema, however, the description does not indicate what the returned stock_item contains or how not-found errors surface, which is the main gap an agent would notice.

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?

There is a single parameter with 100% schema description coverage, so the schema alone tells the agent to pass a stock_item id. The description's 'by id' merely restates this, adding no format, formatting, or scoping nuance (e.g., whether the id is a UUID or a tenant-qualified identifier); baseline 3 applies when the schema does the work.

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 (Read) and resource (stock_item) with an explicit scope of 'one ... by id', which implicitly separates it from stock_item_list and stock_item_search in the sibling set. It does not name those siblings or otherwise differentiate explicitly, so it falls short of a 5.

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 phrase 'by id' implies this is the direct-lookup path versus the list/search siblings, but the description never says when to use it, when not to, or which alternative to pick when the id is unknown. Usage must be inferred from the name and parameter.

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