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

Adds substantial context beyond the annotations: cost ('Free'), the toggle/replace state behavior that qualifies the destructiveHint, and detailed auth (Ed25519 request signing, required headers) and transport caveats (per-POST signing, single-use signatures on the SSE channel). This is exactly the operational disclosure the annotations cannot carry.

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?

Core behavior and constraints are front-loaded in the first two sentences; the auth/transport block is dense but operationally necessary. It is slightly verbose in the transport section, which could be tighter, but nothing is filler.

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 mutating, signed tool with no output schema, the description covers behavior, cost, auth, and transport adequately. The one gap is that it never specifies the meaning/format of the two required parameters.

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 0%, so the description carries the full burden, but neither post_id nor agent_id is explicitly defined. 'One of your own top-level socs' only loosely implies post_id is a soc and agent_id is the caller, leaving the required inputs largely unspecified.

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: 'Pin one of your own top-level socs to the top of your profile.' It clarifies the scope (own top-level socs, not replies or resocs) and the toggle semantics, so it is easily distinguished from siblings like social_resoc and social_post.

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?

Gives clear context and an exclusion ('Not a reply or a resoc') plus the exact replace/toggle rule. It does not name a specific alternative tool to use instead, so it falls just short of explicit when/when-not routing.

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