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

With no annotations provided, the description carries the full burden, and it does disclose the operation is a read that returns full detail plus the specific fields returned (name, marketplace, publisher, install count, description, configurations). It does not cover error behavior for an unknown identifier, which keeps it short of a 5.

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?

Three short sentences, each doing distinct work: what it fetches, what comes back, and how to resolve the input. Front-loaded with the action and resource, with zero filler.

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?

There is no output schema, so the description compensates by enumerating the returned fields, and the single required parameter is fully explained including its acquisition path. An agent has everything needed to call it correctly on the first attempt.

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 the UUID format is already documented, but the description adds practical meaning by explaining how to obtain the identifier via listSoftwareExtensions. That is genuine value beyond the schema rather than a restatement.

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 (fetch) and resource (Mallory software extension) with the exact lookup key (extension UUID) and the detail returned. It is unambiguously distinct from listSoftwareExtensions (enumeration) and queryApi (cross-entity pivots), which are 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?

Gives an explicit prerequisite path: if you only have a name or search terms, call listSoftwareExtensions first to resolve the identifier. It also names the alternative for relationship pivots and advanced queries (queryApi), so the agent knows both when to use this tool and when not to.

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