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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely new context: the stream is append-only and scoped to tracked official servers within a bounded recent window. It does not state what an omitted days value defaults to.

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?

A single dense sentence with the core scope front-loaded and no filler. The parenthetical list is long but each item earns its place by defining what counts as a change event.

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?

Annotations are rich and parameters are few, but there is no output schema, so the description bears more of the burden for describing what an event record contains; it names event categories but not the event shape or ordering. The unstated default for days is a real gap for a zero-required-parameter tool.

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?

With 0% schema description coverage the description must carry both parameters, and it does give both meaning: days as a lookback window and entry_id as an id sourced from find_mcp. However, it omits the default when days is omitted and never mentions the 1-90 bounds, so an agent must open the schema anyway.

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+resource ("append-only change events of tracked official MCP servers") and enumerates the dimensions tracked (terms/pricing pages, cross-border reachability, tools, status, directory listing). It also distinguishes itself from the sibling find_mcp, which supplies the entry_id rather than returning the events.

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?

"for the last N days, optionally for one entry id from find_mcp" makes the usage pattern and the chaining dependency on find_mcp explicit. It stops short of naming exclusions or when to prefer siblings like list_price_changes over this tool.

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