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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower. The description usefully adds the sort order ('highest price first') and that it mirrors the PlanLimits picker, but says nothing about behavior when no plan fits the budget or how many results come back.

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 the filter, time basis, and ordering packed in without filler. The parenthetical reference to the PlanLimits picker is slightly insider jargon but adds a useful consistency cue.

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 2-parameter tool with no output schema and 0% schema description coverage, the description should at minimum explain the 'use' parameter and the empty-result case. Neither is present, so the definition is thin for a tool whose schema does no explanatory work.

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 0%, so the description must carry the parameter burden. It clarifies budget_usd as a monthly USD figure, but the 'use' enum (individual/team/any) is never mentioned or explained, leaving half the parameters undocumented anywhere.

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 states a specific resource (plans) and scope (priced at or under a monthly USD budget), plus the sort order. It is clear what the tool returns, but it never distinguishes itself from the sibling list_plans, so an agent must guess whether this is the filtered/sorted variant or a duplicate of the plain listing.

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 and no mention of alternatives, even though list_plans and get_tool_plans are obvious candidates for the same intent. The reference to the 'PlanLimits budget picker' points at an internal UI feature rather than telling the agent when to prefer this tool.

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