snapshot_stats_report

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

With no annotations, the description carries the full burde. It clearly implies a read-only computation ('Compute stats') and lists what will be computed, which is decent transparency for a report tool. However, it doesn't disclose edge-case behavior such as error handling for non-existent snapshots, whether duplicates are counted by URI or by other criteria, or whether the operation is side-effect free beyond the implication of 'compute'.

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 sentence with a clear verb–resource opening, followed by a compact enumeration of the computed stats. Every word is functional, and there is no filler or repeated schema information.

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 simple 2-parameter tool with complete schema descriptions, the description covers the core purpose and expected results (the stats list). The response_format parameter already explains output variants, so the lack of an output schema is not crippling. Minor ambiguities around duplicate definition and error behavior are the only gaps.

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 the baseline is 3. The description adds mild value by emphasizing 'one snapshot' and hinting that 'added_at dates' are part of the computed statistics, but it does not meaningfully elaborate on the response_format parameter or the acceptable forms of the snapshot parameter beyond what the schema already states.

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 opens with a specific verb and resource ('Compute stats for one snapshot') and then enumerates precise output metrics: track count, unique URIs, duplicates, and oldest/newest added_at dates. This clearly differentiates it from sibling snapshot tools like snapshot_diff_summary (diffs) and snapshot_integrity_check (integrity).

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?

The phrase 'for one snapshot' implicitly limits usage to a single snapshot and excludes comparison/diff workflows, but no explicit alternatives or when-not-to-use cases are named. An agent can infer context, but the description doesn't actively route to siblings such as snapshot_dif_summary for diffing.

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