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

With no annotations provided, the description carries the full burden of behavioral disclosure. It implies a read-only operation with 'Returns', and it hints at conditional visibility ('returned to a caller with a contribution already on file'), but it does not explain auth requirements, what counts are compiled, or whether any state changes occur.

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?

The description is short and front-loads the main purpose, but the second sentence is awkwardly structured and hard to parse. There is no wasted verbiage, yet the wording sacrifices clarity for brevity.

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 tool with one optional parameter and no output schema, the description leaves important questions open: What exactly are the counts? What happens when name is omitted? What does the returned data look like? Without annotations, richer context is needed but absent.

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 the baseline is 3; the schema already explains that name is the contributed name when no claimed name/key is sent. The description adds only that name selects which record to look for, which is marginal extra meaning.

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 first sentence states a concrete action ('Returns counts of what callers have done here'), but the resource and the exact quantities being counted remain vague. The second sentence about 'records themselves' muddies the purpose, and the description does not differentiate this from siblings like check or who_else_is_here.

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?

No explicit guidance is given for when to use commons versus any of its many siblings. The only usage hint is that 'name selects which one to look for', which is more parameter guidance than tool-selection guidance.

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