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

Annotations already declare readOnly/idempotent/non-destructive, so the description's added value is the temporal contract (weekly snapshots, as-of-day semantics, never today) and the payload content (the biggest driver, the delta between two days, the matches in between). What it lacks is any sense of how far back the series goes or how the result is shaped, which matters since there is no output schema.

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 behavior and the exclusion up front, and every clause carries operational information. The opening sentence is dense and slightly convoluted ('one a week, each as of its day'), and the third sentence partly re-covers ground already stated, but no sentence is expendable.

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 does the work of describing returns: a weekly series plus the dominant mover and the supporting matches. Two optional parameters and a clear boundary against project_standings round it out; only the lookback depth and output shape remain unspecified.

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 both parameters are fully documented there. The description restates the team/default behavior ('Pass the team, or nothing for the member's own team') without adding format or resolution detail, and says nothing at all about the `asked` parameter. 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 (a team's historical playoff chances), fixes the granularity (one per week, each as of its day), and names a sibling tool that covers the case it does not. An agent can distinguish it from project_standings without opening either 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?

Explicitly says when to call it ('how a team's playoff chances have changed, or what its chances were last week') and when not to ('It never gives today's chance'), routing the excluded case to project_standings. It even signals the Desk Pass requirement attached to that alternative.

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