get_stats

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

Annotations already declare readOnly/idempotent/non-destructive, and the description still adds real context: the loaded-design precondition, pagination via has_more/next_cursor, and the non-obvious counting rule that register bits exclude memories with unknown counts broken out. It does not say what happens for an invalid or non-existent path, which keeps it below 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?

Front-loaded with the core purpose, then siblings to avoid, then return shape and the register-bit caveat. Information-dense with no filler, though the second sentence is a long run-on that could be split.

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?

No output schema exists, and the description compensates by enumerating the return fields (root_model, flat totals, models list, total_models, has_more, next_cursor). Combined with the loaded-design prerequisite and sibling routing, an agent has everything needed to call it correctly.

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 description coverage is 100%, so all three parameters (path, limit, cursor) are already documented inline. The description restates the path default at design level but adds no format, syntax, or path-resolution detail beyond the schema, 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 and resource: 'Summarize instance population by model below `path` or the top design.' It also names exactly what the summary contains (leaf/sequential/model counts, register bits, RAM/ROM), which separates it from the hierarchy and port-card siblings.

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?

Explicitly routes the agent: use this for aggregate counts, use get_hierarchy for actual child instances, get_module_card for one model's ports. The 'requires a loaded design' precondition is also stated, so there is no inference left.

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