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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that the page is public with a historical writeup and no price guide, which is useful framing, but it discloses nothing about rate limits, pagination, auth, or what a missing/invalid id returns. Adequate but not rich beyond the annotations.

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?

Two tight sentences with no filler. The resource identification is front-loaded, the sibling contrast follows, and the parameter note closes it out — every sentence earns its place.

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 single-parameter detail-fetch tool with an output schema present, the description doesn't need to explain return values, and it correctly identifies the resource, its content, and the id's origin. What's missing is edge-case behavior (invalid id, no result), which is minor given the tool's simplicity and the output schema.

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 0% and the schema only types the field as a string, so the description carries the burden: it explains that subject_id is a numeric id sourced from a psa_ticketfacts_subjects result. That materially clarifies the single parameter, though it doesn't address the string-vs-numeric mismatch or what happens with an unknown id.

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 description names a specific resource and form ('One event's full public ticket reference page') plus what the page contains (PSA's historical writeup of the event and the tickets involved). It actively differentiates from the most likely sibling by noting it carries no price guide, unlike psa_autographfacts_subject, so an agent can distinguish it without opening 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?

It states where the required input comes from ('the numeric id from a psa_ticketfacts_subjects result') and draws an exclusion against a sibling tool. It stops short of an explicit when-to-use-this-vs-that rule or workflow sequencing (e.g. call subjects first), so it's clear context without full routing.

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