Unified per-URL snapshot

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds that sources are best-effort (omitted if env vars missing) and that persist optionally writes to a local DuckDB cache, which is a side-effect not captured by annotations. No contradictions.

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 description is three sentences: the first details purpose and sources, the second explains best-effort behavior, and the third summarizes read-only nature and cache option. Front-loaded with key information, no redundant words.

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?

Given the tool's complexity (multiple sources, optional caching, best-effort), the description covers input parameters, behavior, side-effects, and outputs comprehensively. The output schema exists but is not shown; the description still lists expected metrics. No 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 coverage is 33% (only 'url' described). The description adds meaning for 'window' (30/60/90-day) and 'persist' (opt-in DuckDB cache), and explains the URL role. It clarifies the overall context (snapshot across sources) beyond the schema, compensating for missing parameter descriptions.

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 clearly states the tool pulls a 30/60/90-day snapshot for one post across multiple signal sources, listing specific metrics (GSC clicks, Matomo visits, etc.). It distinguishes from siblings like 'posts.list' or 'posts.decay_curve' by focusing on a comprehensive per-URL aggregation.

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 description implies usage for a unified snapshot of a single post's performance but does not explicitly state when to use vs. alternatives like 'gsc.quick_wins' or 'posts.verdict'. No when-not-to or exclusion criteria are provided.

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