read_media_usage

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuinely useful behavioral context by disclosing the exact data surfaced, notably the count of files the server does not have, which is non-obvious and helps the agent decide when this report is worthwhile.

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 front-loaded sentence with a tight enumerated list; each item (space/quota, file count, missing files, per-file limits) carries distinct information. It is dense but not padded, though the colon-list style reads as slightly itemized rather than prioritized.

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 usefully carries the return-value burden by naming the reported fields. It stops short of stating units, formatting, or whether a profile argument is implicitly resolved, but for a zero-arg read report it is largely sufficient.

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 per the rubric the baseline is 4. There is nothing parameter-related for the description to clarify or omit.

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 the specific resource (photo/video storage for the profile) and enumerates exactly what it reports: space used, quota, referenced file count, missing files, and per-file limits. It is clearly a read/report tool, but it does not distinguish itself from siblings like read_instance, which also appears to expose instance-level limits, nor from read_profile.

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 when-to-use guidance, no statement of prerequisites, and no mention of any alternative (e.g. read_instance for instance limits, or delete_media_sweep for cleaning up missing media). The agent must infer usage entirely from the resource name.

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