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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds real value beyond them: the CSV endpoint, the fact that expired_no_jury and unknown are reported separately and never bucketed, and the aggregation granularity limits. What's missing is any note on cost, caching, or size of the response.

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 purpose and the distribution caveat are front-loaded, and each clause (age definition, band list, excluded categories, output fields, CSV path) carries distinct information. The first sentence is long and clause-heavy, which slightly hurts scanability, but there is no filler.

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 takes on the burden of describing returns and does so explicitly: band labels (0, 1, 2-3, 4-7, 8-15, 16+), answers, share, median_age_epochs, settled, juried, closes, first_close, plus the out-of-band expired_no_jury and unknown counts. Nothing an agent needs to call or interpret it 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 description coverage is 100%, so dir, sort, and segment are fully documented in the schema, including the segment genesis-cut caveat. The description adds nothing about parameter behavior itself (it only mentions reusing the Settlement view's origin bucketing), so the 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?

Names the exact resource (settle age distribution) and defines the metric precisely: 'age in epochs = settle close minus origin epoch'. It also scopes it as 'network-wide' and explicitly contrasts with per-entity views, so an agent can tell it apart from get_settlement_by_origin and get_grade_history.

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 it to see how long answers sat before grading settled them' gives an explicit use case, and 'A distribution only: no address, no verdict, never per grader' rules out the main misuses, implicitly routing those questions elsewhere. It does not name the alternative tools by name, so it falls short of a 5.

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