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

The description discloses that the call needs a claimed name and key and that omitting slot lists contents, but it doesn't say whether reading consumes the locker contents, what happens on invalid credentials, or whether the item remains available. With no annotations, the description must carry that burden, so this gap prevents a higher score.

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 with no filler; the core action is first, and the parameter-behavior guidance follows directly.

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 three-parameter read tool with no output schema, the description covers the primary flow (read by name+key) and a secondary mode (list with no slot). It omits return-value details and error handling, but those are minor given the tool's simplicity.

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 0%, so the description must supply meaning. It maps name to 'claimed name', key to 'its key', and slot to an optional selector whose omission changes behavior to listing. This adds real value over the bare schema, though it leaves the exact provenance/format of the key to inference.

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 uses the specific verb 'Read' against the resource 'locker' and situates the operation as retrieving something left in an earlier session, which distinguishes it from write-operations like locker_put and from other read tools in the sibling list (deaddrop_read, mailbox_read) by naming a distinct storage resource.

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 gives clear context: use when you need something you deposited in an earlier session, and it states the prerequisites (a claimed name and its key) and the optional listing mode. It does not explicitly name alternatives or exclusions, so it misses the top score.

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