upc_capabilities

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

The annotations already declare readOnlyHint=true, destructiveHint=false, so the safety profile is covered; the description usefully adds that the call is local and issues no school/network request, which is real context an agent can act on. However it says nothing about what the response contains, and there is a mild tension between 'no school request' and openWorldHint=true, which suggests an externally-facing call.

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?

A single compact sentence with the resource stated first and the scoping clause second — zero filler. It is arguably too terse, since a few more words defining 'capabilities' would have cost little and removed ambiguity.

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 parameters and no output schema, the description carries the full burden of telling the agent what comes back, and it does not — 'capabilities' is never unpacked into concrete fields. For a cheap discovery tool this is a noticeable gap, since an agent must call it blind to learn whether it answers its question.

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?

The tool takes zero parameters, so there is no parameter semantics to document and the baseline of 4 applies. Nothing in the description is needed to disambiguate an empty argument object.

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?

Uses a specific verb ('Read') with a named resource ('local implementation/authentication capabilities'), and the trailing clause 'makes no school request' separates it from every network-bound sibling in the upc_* family. What is still fuzzy is the word 'capabilities' itself — an agent can't tell whether that means auth/session state, supported feature flags, or implementation version.

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?

There is no explicit when-to-use statement and no named alternative, but the 'local ... makes no school request' framing implies a discovery/diagnostic role — call it when you need to know what is available or authenticated before hitting the school-facing tools. That inference is reasonable yet left entirely unstated.

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