list_installed_packages

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is fully covered. The description adds one genuinely useful behavioral fact beyond that — only explicitly installed packages are returned, not dependencies — but says nothing about default result capping, truncation, or ordering, which matter for a list operation.

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 front-loaded sentence with no filler. It is appropriately sized for a two-parameter read tool, though it spends its only clause on optionality that the schema already conveys.

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 read-only list tool with full schema documentation and no output schema, the essentials are present. The gap is sibling disambiguation against search_package and any hint about result ordering or completeness, which an agent choosing among these listing tools would want.

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%, with both 'limit' (default 50) and 'filter' (substring match) fully described in the schema. The description only restates that filtering is optional and by name, adding no syntax, matching rules, or interaction with limit, so baseline 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 (list) and resource (installed packages) with a meaningful qualifier: 'explicitly installed', which excludes dependencies. An agent can distinguish it from general listing tools, though it never names the closest sibling (search_package) to sharpen the distinction.

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 'explicitly installed' implicitly signals when this is preferred over a broad package search, and 'optionally filtered by name' hints at the filter parameter's use. But there is no explicit when-to-use/when-not guidance nor any mention of search_package as the alternative for broader or non-installed queries.

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