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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds one genuine behavioral fact — results are ranked by count — which is not in the annotations or schema. It says nothing about how the count is computed, whether results are truncated, or how ranking interacts with the days window.

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?

One short sentence with the core behavior front-loaded and no filler. The dash-clause of examples is slightly telegraphic but earns its place by showing the substring format.

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 4-parameter read tool with full schema coverage and no output schema, the description is minimally adequate. It omits what 'ranked by count' means (event count over the window) and gives no hint of the return shape or pagination behavior, which an agent must infer from limit.

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 all four parameters (days, limit, query, property) are already documented with semantics and constraints. The description's example substrings (

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 verb and resource (searching events) plus the matching rule (name contains a substring) and the ordering (ranked by count), with illustrative query values. It is clearly distinguishable from list_events, though it never names that sibling explicitly.

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?

Usage is implied by 'whose name contains a substring' — the agent can infer this is for substring lookup rather than enumeration. There is no when-to-use statement, no mention of list_events as the broader alternative, and no note about when a default property is preferable.

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