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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds value beyond that by disclosing what is returned in each mode (titles and image links vs. the image itself), which an agent needs to plan the 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?

Two compact sentences, front-loaded with the resource and then the mode switch. Dense but every clause carries information; no filler.

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 output schema, the description has to convey return shape, and it does: list mode yields titles and image links, single mode yields the image. For a two-parameter read-only tool this is largely sufficient, with only the sibling-relationship guidance missing.

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 100% and the chart_id examples are already in the schema, so the baseline is 3. The description goes further by explaining the behavioral consequence of supplying versus omitting chart_id, which the schema does not state, though it says nothing about how use_case interacts with chart_id selection.

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?

States a specific resource ('the published graphs') and enumerates the content families (overall scorecard, key metrics, per-query grids for GTM, insurance, finance, developer activation). This is clear, but the 'overall scorecard' / 'key metrics' phrasing overlaps conceptually with siblings like get_scorecard and get_overall_results without saying how they differ.

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 does explain the two operating modes implicitly: no chart_id lists charts, with chart_id returns the image. That is usage-relevant, but there is no explicit guidance on when to pick this over get_scorecard or get_overall_results, which are the obvious alternatives for overlapping content.

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