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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add shape information—and it does, by describing the two distinct return shapes: all groups with plan names/refs/urls versus one group with summaries and step counts. It doesn't mention pagination, library size, or failure behavior for an unknown group name, which are the remaining gaps.

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 sentences, front-loaded with purpose, then the usage condition, then the two-mode return contract. The example groups are illustrative rather than padding, and no sentence merely restates the name or title.

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?

With no output schema, the description carries the burden of describing returns—and it does so precisely for both call modes. For a single-optional-parameter browse tool with full annotation coverage, nothing an agent needs to invoke it correctly is missing.

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 schema already explains where the valid group name comes from, so the description could have rested there. Instead it adds meaning the schema cannot: what the absence of `group` yields versus what supplying it changes in the response, which directly informs the agent's decision to pass the parameter or not.

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 ("Browse the public plan library") and immediately scopes it by group with concrete example categories (Basic Manners, Grooming & Handling, Positions, Tricks). The contrast clause "rather than an answer to one problem" separates it from question-answering siblings without the agent needing to inspect any schema.

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?

"Use when the user wants to see what can be trained or what a category holds" gives a clear selection condition, and the contrast with answering a single problem tells the agent when not to use it. It stops short of naming a concrete alternative tool (e.g. search_plans / get_plan), so routing between the plan-family siblings is still partly inferred.

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