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

The description includes a side effect (mark_read:true sets events as read), which contradicts the annotation readOnlyHint: true. According to the rule, a description contradicting annotations scores 1, despite the description itself being transparent. This inconsistency could confuse agents about read/write semantics.

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, front-loaded with the main purpose. Every sentence adds useful context without redundancy. Highly efficient.

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 five parameters, no output schema, and a large sibling set, the description covers purpose, return format, parameter usage, alternative access method, and behavioral side effects. It is thorough for its complexity level.

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%, so baseline is 3. The description adds value beyond the schema by explaining return fields (source, citation_uri, payload) and clarifying the effect of mark_read, earning a slight bonus.

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 fired events from a subscription feed, specifying the verb and resource. It mentions return fields but does not explicitly distinguish from sibling tools like list_subscriptions or recent_changes, which may have overlapping functionality.

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 provides contextual guidance on polling and an alternative endpoint for scripts, but it lacks explicit when-to-use or when-not-to-use instructions relative to sibling tools. No exclusions or alternate tool recommendations are given.

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