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

Annotations already cover safety (readOnlyHint, idempotentHint, destructiveHint false). The description adds operational context beyond that: requires a connected X account, a specific failure mode when account only syncs via browser extension, and the 'server-side' nature. This enriches understanding of how the tool behaves without contradicting annotations.

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?

Four tightly written sentences, each earning its place: core action, prerequisite and failure mode, usage trigger, and sibling differentiation. Front-loaded with the primary purpose; no filler or redundancy.

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 two-parameter fetch tool with no output schema, the description covers the usage trigger, prerequisites, failure mode, and alternative. The annotations cover safety. Nothing an agent needs to decide whether to call or to interpret the outcome is 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% with descriptions for both 'max' (number, min/max) and 'force' (boolean). The description does not add param-specific semantic detail beyond what the schema already provides. Baseline of 3 applies because the schema carries the documentation burden.

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 verb ('force-pull') and resource ('recent bookmarks from the X API'), with a clear scope ('server-side'). It also names the sibling it is not ('For Twitter-list freshness, use get_list_tweets instead'), distinguishing it from other tools without opening schemas.

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?

Explicitly says when to use: 'Use when the user asks to refresh / fetch their latest saves.' It also provides an alternative for a related but distinct use case (get_list_tweets). This gives clear context and an exclusion, leaving nothing to inference.

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