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

The description contradicts the annotations. It says 'Set mark_read:true to flag returned events read so the next call only shows newer ones,' which implies a persistent state change, yet the annotations declare readOnlyHint:true and idempotentHint:true. This is a serious inconsistency that could mislead an agent about side effects.

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 concise and front-loaded: it starts with the main action, then covers return content, filtering, the key behavioral option, and an alternative access method. Every sentence earns its place with no redundancy or padding.

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 has 5 parameters and no output schema, the description covers return format, filtering, mark_read behavior, polling suitability, and an alternative endpoint. It lacks some details (e.g., interaction between mark_read and unread_only, pagination), but is largely complete for a read-oriented tool. The annotation contradiction slightly undermines completeness.

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?

The input schema covers all parameters (100% coverage), so a baseline of 3 applies. The description adds value by explaining the purpose of mark_read ('so the next call only shows newer ones') and gives a concrete example for type ('sec_8k'), going beyond the schema's minimal 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's purpose: 'Pull fired events from your subscription feed' and specifies the return contents (source, citation_uri, raw event payload). This distinguishes it from sibling tools that manage subscriptions or show changes, making the purpose unambiguous.

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 clear usage context: filtering by type and since, using mark_read for read tracking, and notes that polling works fine. It also offers an alternative HTTP endpoint for scripts/dashboards, but does not explicitly mention when to prefer this tool over sibling tools like recent_changes or list_subscriptions.

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